Contact roll for abrasive belt polishing machines



Oct. 11, 1955 CONTACT ROLL E. L- ANDERSON 2,720,061

FOR ABRASIVE BELT POLISHING MACHINES Filed Aug. 25, 1954 INVENTOR.Eugene L. Anderson HIS TTORNE Y8 United States Patent CONTACTRoLLFoRABRASIVE BELT r POLISHlNG MACHINES Eugene L. Anderson,Coraopolis, Pa., assignor to Rockwell Spring and Axle Company,Coraopolis, Pa., a corporation of Pennsylvania Application August 25,1954, Serial No. 452,145

4 Claims. (Cl. 51-141) This invention relates to abrasive belt grindingand polishing machines and, more particularly, to an improved type ofcontact roll for such machines. Abrasive belt polishing machines includea contact roll, a second roll spaced therefrom, an endless abrasive beltpassing around said rolls and means for driving one of them. The Work tobe polished is pressed against the abrasive coated surface of the beltat a portion of the belt which is backed by the contact roll. Thus, thecontact roll does not actually come into contact with the work to bepolished but supports and resists the pressure of the work against theabrasive belt.

Various types of contact rolls have been used in the past. Some of themconsisted of fabric disks such as canvas disks made up of plies offabric stitched together, the disks being mounted on a hub. Rubber disksalso have been employed as contact rolls. Contact rolls have been madecomprising a soft rubber core and a hard rubber facing and the facinghas been grooved or serrated.

The present invention provides an improved form of contact roll whichhas been found to considerably increase the life of the abrasive belts.After such belts have been used for a time, the abrasive coating becomesglazed or otherwise unfit for further use and the belt must be replacedwith a new belt. My contact roll considerably increases the life of thebelt as contrasted with belts used in combination with any of the typesof contact rolls known heretofore.

In the accompanying drawing which illustrates, in a somewhatdiagrammatic manner, a preferred embodiment of the invention,

Figure 1 is an end elevation of the essential parts of an abrasive beltpolishing machine;

Figure 2 is a front elevation and partial section; and

Figure 3 is an end elevation of a modified abrasive belt polishingmachine.

Referring more particularly to the accompanying drawing and for thepresent to the embodiment shown in Figures 1 and 2, an endless abrasivebelt 2 passes around an upper idler roll 3 having a supporting shaft 4and around a lower contact roll 5.1 The workpiece 6 to be polished, suchas a sheet of steel, is pressed against the abrasive belt at the portionof the belt which is backed by the contact roll 5. Pressure is exertedagainst the workpiece by a pressure roll 7 by means not shown. Thecontact roll is driven by any suitable means such as a motor and gearingnot shown.

The contact roll 5 comprises a hub 8 to which the inner ends 9 of wires10 of spring steel or other suitable resilient material are secured. Thewires may be secured to the hub by means of a layer or core 11 ofrubber, the ends of the wires being inserted in the rubber beforevulcanization and the rubber thereafter vulcanized. Any other suitablemeans for securing the ends of the Wires to the hub may be employed. Thewires are closely packed together and in eflfect form a wire brush Wheelin which the outer ends 12 support the inner surface of the abrasivebelt 2, thus providing a resilient support for the belt; Jhub 8 by nuts14 andact to compress the wires 10 mo- .gether and prevent them frombending excessively when 2,720,061 Patented Oct. @1 1, r

End retaining; plates 13 .are secured to the pressure is applied tothe'contact roll.

, :In the use. of the polishinguapparatus, the pressure against thecontact roll causes the wires to bend slightly, thus conforming to anyirregularities in the surface of the workpiece and providing a resilientbacking for the abrasive belt. That portion of the belt in contact withthe contact roll is in effect supported by a multitude of wires whichtend to resist the force applied to the contact roll.

This type of support causes the abrasive grain opposite the wire to beheld against the work at an angle dependent upon the location of thepressure at the base of the grain while those grains not supported arepermitted to recede from the work. On the next revolution of the beltsome of those grains that receded from the work on the previousrevolution will be presented to the work and some of those whichcontacted the work on the previous revolution will be presented at adifferent angle thus presenting unworn and unburnt cutting edges to thework more often than with any other type of contact roll known to me.The presenting of the grain at a different angle also has a tendency toremove burnt metal and burnt grain from the tips of the grain thuscleaning or dressing a cutting point for a following revolution of thebelt. This multitude of small supporting areas presents a differentialof pressure resulting in the orientation of these small hard areas onthe surface of the contact roll, thus providing an improved contactroll.

Referring to the embodiment shown in Figure 3, the machine comprises anabrasive belt 16 passing around an idler roll 17 and a driven contactroll 18 which is of the same construction as described in connectionwith Figures 1 and 2. In this embodiment, the workpiece 19 is pressedmanually against the portion of the belt which is supported by thecontact roll 18 instead of employing a pressure roll such as thepressure roll 7 shown in Figures 1 and 2.

In either of the embodiments shown, the contact roll 5 or 18 can be anidler roll and the other rolls 3 or 17 can be driven. Furthermore, thetwo rolls can be arranged horizontally or in any other angular positionwith respect to each other, the essential feature of the invention beingthe use as a contact roll for an abrasive belt polishing machine of aroll of the type described which is in the nature of a wire brush wheel.

The invention is not limited to the preferred embodiment but may beotherwise embodied or practiced within the scope of the followingclaims.

I claim:

1. An abrasive belt polishing machine: including a contact roll, asecond roll spaced therefrom, an endless abrasive belt passing aroundsaid rolls, and means for driving one of said rolls, wherein work to bepolished is pressed against the abrasive belt at a portion of the beltbacked by the contact roll, the improved contact roll comprising a wirebrush wheel including wires having their outer ends engaging said belt.

2. A polishing machine including a contact roll, a second roll spacedfrom said contact roll, means for driving one of said rolls, and anendless abrasive belt looped around and supported by said rolls, theimproved contact roll comprising a wire brush wheel having amultiplicity of radial wires which at their outer ends engage andsupport the inner surface of the belt.

3. A polishing machine including a contact roll, a second roll spacedfrom said contact roll, means for driving one of said rolls, and anendless abrasive belt looped around and supported by said rolls, theimproved contact roll comprising a wire brush wheel, said wire brushwheel including a hub and radially extending, closely packed, resilientsteel wires secured to the hub.

4. A polishing machine including a contact roll, a

second roll spaced from said contact roll, means'for a driving one ofsaid rolls,- and an endless abrasive belt looped around and supported bysaid rolls, the improved UNITED STATES PATENTS Ross Apr. 9, 1887Sheridan Aug. 13, 1907 Galvin May 13, 1924 Rasmesen June 21, 1927 LoseyJune 19, 1945 Hcrchenrider Aug. 2, 1949 Kimball Oct. 31, 1950

